The present study was conducted to determine the effects of incomplete larval feeding experience with a deterrent plant latex on subsequent adult oviposition behavior. Larvae of the cabbage looper, Trichoplusia ni, were exposed to the latex of Hoodia gordonii at 100ppm in artificial diet. This plant material strongly deters oviposition in naïve moths in laboratory choice tests. Larvae that were “completely experienced” (exposed throughout larval development) showed a decrease in oviposition deterrence response as adults. This effect persisted when larval exposure to H. gordonii latex was suspended for the final two days immediately prior to pupation, but those not exposed for three or more days behaved like naïve moths. Naïve larvae exposed to the latex for their entire final instar showed decreased oviposition deterrence. However, those exposed for less than the entire final instar were deterred from ovipositing on leaves treated with the latex. These observations that adult oviposition choice can be influenced by a change in diet in the final larval instar indicate the presence of a sensitive period whereby larval feeding memory can be lost or maintained in the subsequent adult.